Booth made the announcement at the Statehouse, surrounded by top Republicans including state GOP Chairman Katon Dawson, Lt. Gov. Andre Bauer and Gov. Mark Sanford.

"Like many others who once considered themselves conservative Democrats ... I can no longer support a national party whose foreign policy platform features an early retreat on the war on terror in Iraq and whose national economic plan is to hike taxes on America's middle class," Booth said.

South Carolina Democratic Party Executive Director Nu Wexler said most Democrats are energized after the state's Feb. 3 presidential primary.

"South Carolina Democrats will campaign vigorously this year on national security, fiscal responsibility and better public schools, and we're disappointed that Sheriff Booth doesn't want to be a part of this team," Wexler said.